結果
問題 | No.2337 Equidistant |
ユーザー |
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提出日時 | 2023-06-02 22:25:49 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 1,140 ms / 4,000 ms |
コード長 | 8,883 bytes |
コンパイル時間 | 2,541 ms |
コンパイル使用メモリ | 207,108 KB |
最終ジャッジ日時 | 2025-02-13 19:06:37 |
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 1 |
other | AC * 28 |
ソースコード
#line 1 "main.cpp"//#pragma GCC target("avx")//#pragma GCC optimize("O3")//#pragma GCC optimize("unroll-loops")#include<bits/stdc++.h>#ifdef LOCAL#include <debug.hpp>#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)#else#define debug(...) (static_cast<void>(0))#endifusing namespace std;using ll = long long;using ld = long double;using pll = pair<ll, ll>;using pii = pair<int, int>;using vi = vector<int>;using vvi = vector<vi>;using vvvi = vector<vvi>;using vl = vector<ll>;using vvl = vector<vl>;using vvvl = vector<vvl>;using vpii = vector<pii>;using vpll = vector<pll>;using vs = vector<string>;template<class T> using pq = priority_queue<T, vector<T>, greater<T>>;#define overload4(_1, _2, _3, _4, name, ...) name#define overload3(a,b,c,name,...) name#define rep1(n) for (ll UNUSED_NUMBER = 0; UNUSED_NUMBER < (n); ++UNUSED_NUMBER)#define rep2(i, n) for (ll i = 0; i < (n); ++i)#define rep3(i, a, b) for (ll i = (a); i < (b); ++i)#define rep4(i, a, b, c) for (ll i = (a); i < (b); i += (c))#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)#define rrep1(n) for(ll i = (n) - 1;i >= 0;i--)#define rrep2(i,n) for(ll i = (n) - 1;i >= 0;i--)#define rrep3(i,a,b) for(ll i = (b) - 1;i >= (a);i--)#define rrep4(i,a,b,c) for(ll i = (a) + ((b)-(a)-1) / (c) * (c);i >= (a);i -= c)#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)#define all1(i) begin(i) , end(i)#define all2(i,a) begin(i) , begin(i) + a#define all3(i,a,b) begin(i) + a , begin(i) + b#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)#define sum(...) accumulate(all(__VA_ARGS__),0LL)template<class T> bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; }template<class T> bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; }template<class T> auto min(const T& a){return *min_element(all(a));}template<class T> auto max(const T& a){return *max_element(all(a));}template<class... Ts> void in(Ts&... t);#define INT(...) int __VA_ARGS__; in(__VA_ARGS__)#define LL(...) ll __VA_ARGS__; in(__VA_ARGS__)#define STR(...) string __VA_ARGS__; in(__VA_ARGS__)#define CHR(...) char __VA_ARGS__; in(__VA_ARGS__)#define DBL(...) double __VA_ARGS__; in(__VA_ARGS__)#define LD(...) ld __VA_ARGS__; in(__VA_ARGS__)#define VEC(type, name, size) vector<type> name(size); in(name)#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(w)); in(name)ll intpow(ll a, ll b){ ll ans = 1; while(b){if(b & 1) ans *= a; a *= a; b /= 2;} return ans;}ll modpow(ll a, ll b, ll p){ ll ans = 1; a %= p;if(a < 0) a += p;while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }ll GCD(ll a,ll b) { if(a == 0 || b == 0) return 0; if(a % b == 0) return b; else return GCD(b,a%b);}ll LCM(ll a,ll b) { if(a == 0) return b; if(b == 0) return a;return a / GCD(a,b) * b;}namespace IO{#define VOID(a) decltype(void(a))struct setting{ setting(){cin.tie(nullptr); ios::sync_with_stdio(false);fixed(cout); cout.precision(12);}} setting;template<int I> struct P : P<I-1>{};template<> struct P<0>{};template<class T> void i(T& t){ i(t, P<3>{}); }void i(vector<bool>::reference t, P<3>){ int a; i(a); t = a; }template<class T> auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; }template<class T> auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); }template<class T, size_t... idx> void ituple(T& t, index_sequence<idx...>){in(get<idx>(t)...);}template<class T> auto i(T& t, P<0>) -> VOID(tuple_size<T>{}){ituple(t, make_index_sequence<tuple_size<T>::value>{});}#undef VOID}#define unpack(a) (void)initializer_list<int>{(a, 0)...}template<class... Ts> void in(Ts&... t){ unpack(IO :: i(t)); }#undef unpackstatic const double PI = 3.1415926535897932;template <class F> struct REC {F f;REC(F &&f_) : f(forward<F>(f_)) {}template <class... Args> auto operator()(Args &&...args) const { return f(*this, forward<Args>(args)...); }};//constexpr int mod = 1000000007;constexpr int mod = 998244353;#line 2 "library/graph/graph-template.hpp"template <typename T>struct Edge {int from, to;T cost;Edge() = default;Edge(int _to, T _cost) : from(-1), to(_to), cost(_cost) {}Edge(int _from, int _to, T _cost) : from(_from), to(_to), cost(_cost) {}bool operator < (const Edge &a) const { return cost < a.cost; }bool operator > (const Edge &a) const { return cost > a.cost; }Edge &operator = (const int &x) {to = x;return *this;}operator int() const { return to; }friend ostream operator<<(ostream &os, Edge &edge) { return os << edge.to; }};template <typename T>using Edges = vector<Edge<T>>;template <typename T>using Wgraph = vector<Edges<T>>;using Ugraph = vector<vector<int>>;Ugraph uinput(int N, int M = -1, bool is_directed = false, int origin = 1) {Ugraph g(N);if (M == -1) M = N - 1;while(M--) {int a,b;cin >> a >> b;a -= origin, b -= origin;g[a].push_back(b);if(!is_directed) g[b].push_back(a);}return g;}template <typename T>Wgraph<T> winput(int N, int M = -1, bool is_directed = false,int origin = 1) {Wgraph<T> g(N);if (M == -1) M = N - 1;while(M--) {int a,b;T c;cin >> a >> b >> c;a -= origin, b -= origin;g[a].emplace_back(b,c);if(!is_directed) g[b].emplace_back(a,c);}return g;}#line 3 "library/tree/tree-query.hpp"template <typename G>struct Tree {private:G &g;//G g;int root;vector<vector<int>> bl;vector<int> dp;void build() {bl.resize(g.size());dp.resize(g.size());dfs(root, -1, 0);}void dfs(int c,int p, int dis) {dp[c] = dis;for(int i = p,x = -1;i != -1;) {bl[c].push_back(i);i = ++x < (int)bl[i].size() ? bl[i][x] : -1;}for (int d :g[c]) {if(d == p)continue;dfs(d,c,dis + 1);}}public://Tree(): root(0){}Tree(G &_g,int _root = 0):g(_g),root(_root) {build();}int depth(int u) const{ return dp[u]; }int parent(int u) const{ return u == root ? -1: bl[u][0];}int kth_ancestor(int u, int k) const {if (dp[u] < k) return -1;for(int i = k ? __lg(k):-1; i >= 0; --i) {if ((k >> i) & 1) u = bl[u][i];}return u;}int next(int st,int gl) const {if(dp[st] >= dp[gl]) return parent(st);int u = kth_ancestor(gl,dp[gl] - dp[st] - 1);return bl[u][0] == st ? u:bl[st][0];}vector<int> path(int st,int gl) const {vector<int> pre,suf;while(dp[st] > dp[gl]) {pre.push_back(st);st = bl[st][0];}while (dp[st] < dp[gl]) {suf.push_back(gl);gl = bl[gl][0];}while (st != gl) {pre.push_back(st);suf.push_back(gl);st = bl[st][0];gl = bl[gl][0];}pre.push_back(st);reverse(begin(suf),end(suf));copy(begin(suf),end(suf),back_inserter(pre));return pre;}int lca(int u,int v) {if (dp[u] != dp[v]) {if (dp[u] > dp[v]) swap(u,v);v = kth_ancestor(v,dp[v] - dp[u]);}if (u == v)return u;for(int i = __lg(dp[u]);i >= 0;--i) {if (dp[u] < (1 << i)) continue;if (bl[u][i] != bl[v][i]) u = bl[u][i],v = bl[v][i];}return bl[u][0];}int distance(int u,int v) {int ancestor = lca(u,v);return dp[u] + dp[v] - 2 * dp[ancestor];}};#line 86 "main.cpp"int main() {INT(n,q);vvi g(n);rep(i,n-1) {INT(a,b);a--,b--;g[a].emplace_back(b);g[b].emplace_back(a);}Tree<vvi> tree(g);vi ch(n);auto dfs = REC([&](auto &&f,int now,int par) -> void {for(auto &nex:g[now]) {if(nex != par) {f(nex,now);ch[now] += ch[nex];}}ch[now]++;});dfs(0,-1);debug(ch);rep(i,q) {INT(s,t);debug(s,t);s--,t--;int d = tree.distance(s,t);debug(d);if(d % 2) {cout << 0 << '\n';continue;}int ans = 0;if(tree.depth(s) == tree.depth(t)) {int lca = tree.lca(s,t);ans = n - ch[tree.next(lca,s)] - ch[tree.next(lca,t)];}else {if(tree.depth(s) < tree.depth(t)) swap(s,t);int mid = tree.kth_ancestor(s,d / 2);debug(mid);ans = ch[mid] - ch[tree.next(mid,s)];}cout << ans << '\n';}}